问题 选择题

将锌片和铜片用导线连接置于同一稀硫酸中,下列叙述正确的是(  )

A.锌片是正极

B.电流从锌片流向铜片

C.氢气在锌片上析出

D.若锌片、铜片同时有气泡冒出,则说明锌片不纯

答案

A、该原电池中,锌片失电子变成离子进入溶液,所以锌片是负极,故A错误;

B、锌片失电子变成离子进入溶液,所以电子从锌片流向铜片,电流流向与电子流向相反,所以电流从铜片流向锌片,故B错误;

C、电子从锌片流向铜片,所以铜片上有大量电子,氢离子得电子生成氢气,所以氢气在铜片上析出,故C错误;

D、电子从锌片流向铜片,所以铜片上有大量电子,氢离子得电子生成氢气,所以氢气在铜片上析出;如果锌片上有氢气生成,则说明锌片不纯,锌与杂质电解质溶液形成原电池,故D正确;

故选D.

阅读理解

A frightening example of the sea’s power saw 125,000 people die in 12 different countries last week. The terrible disaster was caused when a great earthquake sent tsunamis breaking into Indian Ocean coastlines. Various areas in Sri Lanka, Indonesia, Thailand, India, Malaysia and East Africa have been destroyed by the huge waves. Whole towns were simply swept aside by the power of the water. Cars, trains and buildings could not remain steady, not to say the people who stood in the way.

The earthquake measured 9.0 on the Richter scale and occurred off the coast of Indonesia. It was recorded as the fifth strongest since 1900. Scientists said the quake was as powerful as a million of the atomic bombs that were dropped on Japan during the World War II. “This may be the worst natural disaster in recent history because it is affecting so many heavily populated coastal areas.” said Jan Ege-land, a UN official.

Because such waves hardly happen in the Indian Ocean, there is no system in place to warn coastal people who are about to be hit. Tsunami is a Japanese word. They are usually caused by a sudden rise or fall of part of the Earth’s crust under the ocean. Tsunamis often happen in oceans and they are most common in the Pacific.

Tsunamis can be very long, as much as 100 kilometers. They are able to cross entire oceans without losing much energy. One of the most striking facts about tsunamis is that an earthquake on one side of the Pacific Ocean can cause huge waves on the other side.

When the ocean is deep, tsunamis can travel unnoticed at speeds of up to 800 kilometers per hour. They can cross the entire ocean in a day or less. The wave may only be a few meters high in the ocean, but when it is near the shore and reaches shallow water, the wave builds up very quickly in height.

61. How many countries were stricken by the terrible disaster?

A. 6.                                   B. 12.                   C. 18.                   D. Not sure.

62. All of the following statements are true EXCEPT __________.

Tsunami is a word taken in from Japanese

Tsunamis are quite common in the Indian Ocean

The earthquake measured 9.0 on the Richter scale

No warning system has been set up to watch tsunamis there

63. We can know from this passage that __________.

the earthquake has been the strongest in the last century

the wave soon becomes higher when it reaches the shore

the atomic bombs were more powerful than the earthquake

tsunamis can cross entire oceans with almost the same energy

64. You’ll see the passage in __________ section of a newspaper most probably.

A. Sports                      B. Health               C. News                D. Culture

单项选择题